1. Field of the Invention
Embodiments of the disclosure relate in general to the field of computers and similar technologies, and in particular to software utilized in this field. Still more particularly, it relates to providing a system, method, and computer-readable medium for performing data write and data read operations on a tape storage medium.
2. Description of the Related Art
Tape media continues to provide cost effective and reliable data storage. In recent years the data storage capacity of tape media, such as tape cartridges, has increased. Concurrently, there has been a corresponding decrease in tape cartridge form factors. One approach to increasing the capacity of a tape cartridge in future products is to write more tracks on the tape media. However, assuming the tape cartridge form factor remains constant, then the width of each written track will be reduced as the number of tracks increases.
A known consequence of smaller written track widths is read-after-write operations are more difficult to perform. In prior tape drives, the tape servo system positions the head according to writer elements and the reader elements are assumed to follow the writers. The tape system verifies that the data written to tape is good by immediately reading the data after it is written. However, as the track widths get smaller, the assumption that the reader elements are correctly positioned on the written track may not be valid. Misregistration of the tape due to small amounts of skew may result in the reader being positioned off of the written track, causing the read data to be invalid. Furthermore, as the written track widths get smaller, the effects of tape dimensional stability become more important. As a result, the expansion and contraction of tape with fluctuations in temperature must be factored into the margin between the width of the written track and the width of the read head. Accordingly, the effects of tape dimensional stability can be reduced if the span of the head can be reduced in a tape system, especially if the span of the head can be reduced without changing the format of the servo pattern on the tape.
Known approaches to addressing smaller written track widths in read-after-write operations include using a tilting roller to position the tape media such that there is no skew between the write elements and the reader elements. Another approach is to use a head with dual actuators where the read elements are placed on a separate actuator from the write elements. Thus, a servo system can be used to independently place the written tracks in known locations and position the read elements over the written tracks. However, tape dimensional stability remains an issue, especially if tape dimensional stability problems are consistent over a written tape as it could significantly increase the time required to recover data.